Where Leo and Don Bond
by The-Fourth-Queen
Summary: So Leo, ever the curious turtle, wanted to know why there were bubbles outside of his cold drink. And he rises the question to young Don. But Don's now leaning into his place as genius of the family... and Leo? He's just looking out for his brothers while trying to grow into his own shell. A one-shot drabble about the two turtle tots just enjoying each other.


_So... I was reading a Chemistry text-book out of curiosity, and naturally my mind wandered to the ninja turtles. And this piece was born, where a curious turtle asks his smart brother for an explanation. They're young here, but not babies. Enjoy the drabble!_

* * *

Leo returned to find his cup covered in water droplets. Being witness to many of Mikey's pranks, the turtle tot's mind immediately went to accuse his youngest brother.

Leo poked his glass, watching the droplets trickle down the side to form the smallest of puddles around the base of his cup. He frowned, dragging his finger up to collect a decent sized drop on his finger. Eyeing it suspiciously, Leo slowly moved back, making sure it wouldn't fall to the ground.

It was a remarkable feat to get from the kitchen to Don's room without tumbling over Mikey's toys, Mikey's comic books, or Mikey. But Leo was content not to gloat over his incredible journey of obstacles in favor of bothering his purple banded brother.

Leo used his free hand, eyes still on his drop when he lightly tapped Don's door, "Hey Donnie? Can you check this thing out for me?"

Leo barely glanced up to see his nerdy brother hunched over his bed and head buried in a book. Leo winced- knowing that such an awkward position would put Don's body through so much stiff stress.

Don's head snapped up, his eyes going wide when he gave a quick cry of pain, before putting his head back low, "Ow- my neck!"

Leo shook his head slightly, resisting the urge to lecture his usually smart brother on posture, "I wanna show you something,"

Don slowly lifted his hand and with head still bowed he beckoned Leo closer, "Okay- give it to me,"

Leo journeyed to Don's bed, more aware than ever that the turtle's room was ever cluttered with books, nick-knacks and thing-a-ma-jigs of every odd thing Leo could ever imagine. In fact, as Leo stepped over a concrete brick, he wondered if Mikey's room or Don would be better for a minefield practice.

Nearly stumping his toe on something _luckily_ soft, Leo deemed Don's room to be the worse of the lot. At least Mikey didn't keep _lizard skeletons_ in an open box. At least, Leo _hoped_ it was lizard skeletons- he didn't want to think about what other white bones were in that box.

With one large leap, Leo was standing beside Don's bed. He daren't sit, the bed could hold all sort of creepy things. If it were one thing Leo knew about his odd brothers, was that Don liked to hoard things. More than Mikey did.

They went for a sewer walk? Don comes back with an armful of 'treasures'. Hunting for food? Don picks up a brick. And don't even remind Leo of going to the junkyard. The eldest turtle had the oddest idea of giving Don a free pass to the junkyard for a Christmas gift, but that might have his room far too cluttered to even live in. Maybe Don needed a new room- like a lab or something.

Don cleared his throat, head still painfully bent low, "Uh? Leo? What was it you were trying to show me?"

Leo leaned closer to his brother, hand cradling his water droplet, "What's this?"

Don tried to incline his head, but he couldn't. So Leo had to put one knee on the bed to push his hand under Don's face, "Is it some kind of jelly goo or…"

Don deadpanned, "It's water."

Leo's head shot up, and was met with the side of Donnie's head, "You sure?"

Don nodded- barely- he still couldn't move his neck much, "Pretty sure. But we can't be sure unless we test it,"

Leo shook his head, shoving his drop under Don once again, "You sure? I saw this _outside_ my glass- water goes inside the cup Don. I don't know how it got outside,"

Don's eyes widened, and he turned his entire upper body so that his forehead could face his brother, "Outside? As in spilling?"

Leo clicked his tongue, shaking his head once more, "No… More like…. _Bubbles…_ "

Don's voice was just a tad tired, "Maybe it's Mikey playing a prank,"

Leo couldn't help his smile- of course they would all accuse Mikey, "That's why I came to you- to make sure of it,"

To be honest, Don looked shell of a lot more surprised than Leo thought he would. All wide-eyed and open-mouthed, "Me?"

And the younger turtle spluttered, "Why _me_?"

Leo blinked down at his brother, "Are you seriously asking me that?"

If Don could have nodded, he would have.

Leo sighed, and shook his hand to get rid of the drop so he could lean closer to his brother, tilting his own face so he could finally meet the dark eyes. Dark eyes that looked so confused.

Leo smiled, more like grinned at his brother, "You're the genius out of all of us Don,"

If Don's eyes grew any wider, Leo wouldn't have been surprised if they popped right out.

Leo's smile faded, the mental image of his brother blindly searching for his rolling eyeballs to put it with his lizard skeleton was not a pleasant thought. And Leo locked that idea far away that very well might find its way into his nightmares.

Don's frown deepened, "I'm not smart- Mikey is,"

Leo's grin came right up back, "Mikey's creative all right- but you understand the science stuff better than all of us do,"

Don nearly tilted his head up, but he couldn't. So Leo lay on the bed, his shell uncomfortable, but his head under his brother's face. _Finally_ seeing all of Don's face, but for shell's sake- Leo finally understood why turtles didn't like being on their backs.

But the eldest nodded his head, "You're always collecting things, curious about how they work- and you're the best at solving puzzles!" and just because Don needed a little self confidence boost, he added, "You're a really smart fighter too!"

Don's frown deepened, "No- Raph is a fighter. He beats all of us in sparring,"

Leo's grin slipped right off his face- immediately reminded of how Raphael had thrown him over his head and sent him tumbling into the rack of weapons and the very reason why he needed to take a refreshing glass of water. So he could… and Leo quoted Raph here, " _Cool your shell,_ "

Leo's shell was cool enough- thank you very much.

Don spoke again, snapping Leo from his thoughts, "I'm not as strong as Raph, not as creative as Mikey and certainly nothing like you… I'm just…"

Leo waited for the complementary adjective about Don, but after a few seconds of hearing nothing, he goaded his brother, "But nobody's handy like Don,"

"Am not! I'm useless."

And Don pitched back onto his surprisingly clean pillow and started shaking with what Leonardo _knew_ where tears. And for a moment, the eldest was shell-shocked.

Leo's face fell, and he cast a longing look at the door- where his glass of water still (hopefully) mysteriously sat waiting for one thirsty turtle to consume it.

Leo came to find answers about the possible poisoning of his water, and was instead met with the melodrama of his younger brother. If Leo could have given a dramatic sigh- he would have. But drama was Mikey's thing- Leo had his own thing going on… like…

Don hiccupped, "I'm not perfect like you either Leo!"

This had Leo shooting up, "Huh?"

His finger slammed against his own plastron, "Me? _Perfect?_ "

Leo resisted the urge to whine- because _perfect_ people did _not_ jam their delicate fingers against stiff plastrons and bend them back to near-crying-pain. Leo kept a straight face, and he coolly repeated, "I'm not perfect,"

 _Ow his finger. Ow his finger. Ow his finger._

Leo crawled over to Don, smoothly avoiding the books and suspicious brown smudges. But it didn't smell- so Leonardo was very happy to assume that it was not anything disgusting.

The elder turtle reached out to rub his brother's shell, with Don still keeping his head buried low into the pillow, complaining all sorts of things that Leo couldn't hear. Frankly, that was good, because Leo wasn't sure how to answer.

 _Ow-his-fing-ger_.

Leo grit a smile out at his brother, "Don't be like that Don, we all have our places in this family,"

A sniff from Don, and a mumble. Leo leaned closer just enough to hear, "Not me!"

And Leonardo sighed long and deep- the air escaping his mouth in drama that Mikey would have been proud of, ending with the finishing touch of dropping his chin onto his shell.

A clank was heard as Leo's chin hit the top of his plastron. He winced again, teeth grit as he recalled what a stupid idea it was to drop his _soft_ chin against _rock-hard_ plastrons.

Leo murmured something so low that he didn't want Donnie to hear- because he didn't want to explain why something hurt like a female dog, and he didn't want to explain where he heard something like that from.

 _Ow-his-finger. Ow-his-chin._

Don turned over on his shell, his back gratefully flat as Leonardo noticed, "What's pain got to do with a b…"

Leo burst out, "Nothing!"

And Don was left blinking up at his brother, his head slowly trying to rise but still resting on his plastron. His _normally-sized_ plastron, Leo noted.

Don's eye ridges met, and Leo was once again victim to his scrutinizing gaze, "Hey Leo…"

"Yes Don?"

"Why haven't you grown into your shell as yet?" Don's eyes practically shimmered, "It's too big and lanky for your body,"

Leo's frown was deep enough to compete with the Marianna Trench- and how-the-shell did he even know what that Trench was. All he cared about at the moment- was Don pointing out a painfully obvious fact. Leo _knew_ his shell was awkward and Master Splinter promised him that he would grow into it like his brothers had done.

Don's eyes lit up, "Are you deformed or something?"

Leo deadpanned, "Insensitive much?"

And at that, Don gave a sheepish smile, but he sat up, "I'm just curious,"

Leo folded his arms, but he couldn't help his tiny smile, "Why don't you go research and find out?"

Don's eyes widened, and it would have been a cute sight if his head was still not resting on his plastron due to the stiff muscle, "Research?"

Leo took full advantage of his ability to nod, "Yep," and the turtle gestured to a book near his leg, "You've got so many scientific things, why don't you research and find out?"

Don rubbed the back of his neck, though Leo wasn't sure if it were a sheepish action or Don releasing his pain, "Gee Leo… I don't know…"

Leo sighed again- this one quicker and less dramatic, but he reached out his aching finger to poke Don's shell, and he ignored the shooting pain in his bad decision all for the sake of emphasis for his word, "Go find things out Don, and try applying them this time,"

Leo retracted his finger, resting his hand on his own leg, "Maybe you should use all that knowledge you have to help people out,"

 _Like explaining why there were bubbles outside of Leo's cold glass_.

Don sighed, his shoulders droopy, "How am I supposed to do that? I just like knowing stuff,"

Leo shrugged, eyes lifting to the ceiling before flickering down at his brother, "Well just combine all the stuff you know, and keep the things that make sense to explain something,"

Don's face was not blank- but it was tired. Leo pouted- at this rate, he would _never_ cheer Donnie up, nor find out what the shell Mikey did to his water.

And Leo's thought drifted back to the kitchen, where he was sure that all the water must have either been stolen, or evaporated. Wait- water only evaporated in the heat. And while the lair was _hot_ , it wasn't boiling in any way.

Leo's eye ridges scrunched up, his aching finger resting on his smarting chin in a poor decision to think, "Hmm…"

Don caught his brother's look, and the younger turtle was now hooked, "Whatcha thinking Leo?"

Leo didn't hesitate to ramble his thoughts, "My water- I remember the glass was cold- but no ice. And you remember how water evaporates in heat and turned into the water vapor… right?"

It was like a light bulb switched on in Don's brain, and though the turtle had head bent, his voice tumbled out, "The Water Cycle. I read it in a book- evaporation turns the liquid into gas, and then the gas in the atmosphere cools back into liquid. Then it falls to the earth as rain- where the whole cycle starts again!"

What Leo wouldn't give to see Don's face light up like that in full- the only current problem was that half of the turtle's face was hidden because of his bent head. But still Leo watched on with the proudest of faces.

"Good Don!" and Leo figuratively pulled Don in his current dilemma, "Now we know that water vapor cools back…"

Don corrected him, "Condenses,"

"Yeah- condenses in cool to form back liquid right…"

Don brought his own hand to the front of his face, fingers moving rhythmically before him, "Hmm… but your cup wasn't permeable so…"

Leo nearly drew a blank- _what was permeable? Oh right… Something about allowing water to pass through it… or having tiny holes… right?_

Don continued as such a rate that Leo had to pick and choose what words to try to understand. But somehow Don got all the way to molecules then _elements of the periodic table_ before Leo put a literal clamp over his mouth.

Don mumbled something but Leo didn't move his hand for a while, "Take it easy Don! Just use the facts that _relates_ to the topic."

Then Leo withdrew his hand- mentally cursing for applying pressure to the now-revived pain of his hand. At least Don wasn't heading off to the moon.

But Don was quiet- his shoulders slumped as though Leo put a permanent hold to all his thoughts. And it was then Leo realized his mistake.

The elder turtle lifted his hands in surrender, " _Or_ maybe all those topics _are_ important," and he narrowly glanced to the side, "Maybe it's _your_ way of figuring things out,"

And Leo added softly, "You _do_ know a lot of things,"

It worked, and Don was smiling again. Smiling _and_ blabbering again. And Leo didn't mind one bit that Don was reciting something about states of matter and kinetic theory. Whatever it was- it must have been related to Leonardo's dilemma.

At least _now_ he was sure that Mikey was innocent. And an innocent Mikey is a rather cute thing. Leo rested his cheek in his hand, watching as Don tried every few seconds to lift his neck but always ending up wincing in pain- even when he tried to reach for a ragged text-book under his pillow.

Leo giggled, and crept close to his brother to place his hands on the back of his neck. At first, Don stiffened, but after a few comforting words, Leo managed to persuade Don into a gentle massage. Mainly because Leo couldn't bear seeing Don in such pain.

It wasn't hard- Leo liked pressing his hands on Don's soft skin, feeling the bones beneath and rubbing out tense knots.

And while Don spoke, Leo listened. It was more than endearing to hear his brother speak with such zest, a tone of utter fascination and honestly? It was educational.

And Leo couldn't deny that he was just as curious as Don was- but not up to the hoarding part. And while Leo was a bit creative, he couldn't coax masterpieces out on a page like Mikey could. Leo might have been a good fighter- but he knew he could never be as strong as Raph pounding his new punching bag.

And Leo was okay with that. He preferred watching his brothers excel at things, and who knows, maybe Don might even discover or invent new and helpful things? The turtle had a beautiful mind- one that should be encouraged to be free.

Just as long as he didn't keep too many lizard skeletons in his room.

Sure science was weird, but Don had to draw a line between his bedroom and a storage room. And the thought of making Don a lab was more and more appealing to Leonardo.

Don gasped, and Leo leaned forward to peer over his brother's shoulders, "Find something?"

Don could finally nod- and Leo was proud, "Yeah Leo, and listen here… you see the bubbles outside your glass?"

Leo nodded slowly, "Uhuh…"

"They were formed through condensation!" Don's face stretched into a giant grin, "Remember that water vapor is always in the air…?"

 _Huh?_

And then… somehow… it clicked.

Leo's eyes widened and his grin was rivaling Don's disco eyes, "You mean when the water vapor in the air comes close to the cold glass, it just cools down into liquid water?"

Don nodded eagerly, "Exactly! And all the molecules clump together when it does!"

Don jumped up from the bed, "Leo! We're geniuses!"

And Leo would have jumped up, but he didn't want his foot to land in some icky brown mess that was looking less and less appealing with every passing second. But what was wonderful to Leo, was that Don never again had to question his place in the family.

Leo laughed, "Now you can go find out all kinds of things,"

Don gasped, his eyes near boggling, "I could finally find out why the fridge keeps food cold! Or why oil and water doesn't mix! Or why…"

Leo slid off the bed tiptoed around the minefield, and slipped out the door, but not before giving Don his proudest smile. Today… in that moment… a genius got a glimpse of the endless possibilities of himself.

…


End file.
